There is a continuing requirement for maneuvering pleasure and working vehicles in confined spaces such as in parking, positioning and load handling. It is often the case, that the operator cannot clearly see the ends of his vehicle or potential obstacles in the path of movement.
Decorative or utilitarian features of driver occupied and adjacent vehicles, or fixed objects, are all expensive to repair, and are easily and frequently damaged by vehicle operation, particularly in close quarters. In loading, and similar working situations, it is important to position the vehicle quickly and precisely even though the operator cannot observe the relationships as he maneuvers. Resonant devices such as spring feelers or bumper and fender "Whiskers" are limited by their mounting, fixed length, and dependence upon significant abrasive relative motion between the feeler and the obstacle.
It is desirable, therefore, to have a detector that will sense the presence of an obstacle that is approached from head on, or any angle, and that will quickly give a positive audible warning independent of relative motion. Such a device is particularly desirable where the result is attained without requiring additional parts by utilizing the existing vehicle horn as a warning device.
Additional desirable features of the invention include integrity from water and road hazards, compactness, and ease of mounting on or through the vehicle bumper or other exterior component. The detector is versitile in that warning time to obstacle contact may be easily varied, and the sensitivity of the device changed to fit anticipated conditions or requirements.
The detector is adaptable for use on fixed objects requiring protection from vehicle movement. It may also be used to activate a wide variety of warning sounds, displays, or signals. In vehicle application, its control feature could be used to shut down motive power.